Most films use either a casting agency or a casting director to find actors to match the roles in the film, apart from the lead actors, who are often chosen by directors and producers. The job of a casting director is to know a lot about a lot of actors, so that they can advise and present to the director the best of the available talent. Casting directors are highly influential and are usually on the project because the director trusts their judgement; they are also the ones who decide who the director does see.